A stable donor–acceptor coordination complex of the elusive parent inorganic iminoborane HBNH (a structural analogue of acetylene) is reported. This species was generated via thermally induced N2 elimination/1,2‐H migration from a hydrido(azido)borane adduct NHC⋅BH2N3 (NHC=N‐heterocyclic carbene) in the presence of a fluorinated triarylborane. The mechanism of this process was also investigated by computational and isotopic labeling studies. This transformation represents a new and potentially modular route to unsaturated inorganic building blocks for advanced material synthesis.

ABSTRACT:The electrochemical production of hydrogen peroxide can be implemented in small-scale plants under "on demand" approach. For that, selective catalysts for the oxygen reduction reaction (ORR) towards the desired species are required. Here, we report about the synthesis, characterization, ORR electrochemical behavior and reaction mechanism of an aza-fused π-conjugated microporous polymer, which presents high selectivity towards hydrogen peroxide. It was synthesized by polycondensation of 1,2,4,5-benzenetetramine tetrahydrochloride and triquinoyl octahydrate. A cobaltmodified version of the material was also prepared by a simple post-synthesis treatment with a Co(II) salt. The characterization of the material is consistent with the formation of a conductive robust porous covalent laminar poly-aza structure. The ORR properties of these catalysts were investigated using rotating disk and rotating disk-ring arrangements. The results indicate that hydrogen peroxide is almost exclusively produced at very low overpotential values on these materials. Density functional theory calculations provide key elements to understand the reaction mechanism. It is found that, at the relevant potential for the reaction, half of the nitrogen atoms of the material would be hydrogenated. This hydrogenation process would destabilize some carbon atoms in the lattice and provides segregated charge. On the destabilized carbon atoms, molecular oxygen would be chemisorbed with the aid of charge transferred from the hydrogenated nitrogen atoms and solvation effects. Due to the low destabilization of the carbon sites, the resulting molecular oxygen chemisorbed state, which has the characteristics of a superoxide species, would be only slightly stable and would promote the formation of hydrogen peroxide.

In this work, a series of naphthalimide fused thienopyrazine derivatives was designed, and their synthesis and characterization are reported herein. The interaction of this building block with a donor terthiophene...